1. Field of the Invention
The present invention is directed generally to sound suppressors that are designed for removable attachment to the threaded end of the barrel of a firearm, particularly a rifle. The present invention also concerns suppressors having the capability for suppressing the rather harsh sound of firearm discharge, but also substantially eliminating the rather bright flash that is generally projected from the bore of a firearm barrel when the firearm is discharged. More specifically, the present invention concerns a suppressor device that divides the propellant gas discharge of a firearm barrel into primary and secondary paths that have different discharge openings and serve to lower propellant gas pressure within the suppressor and minimize discharge sound and substantially eliminate propellant flash and minimize the potential for propellant gas blow-back toward the firearm user.
2. Description of the Prior Art
A significant number of firearm sound suppressor devices and flash suppressor devices, generally referred to as suppressors herein, have been developed over the years for use with firearms such as rifles, shotguns and handguns. In most cases the suppressors are attached to the barrel of a firearm, such as by threaded attachment. In some cases suppressors are constructed integrally with a firearm barrel so as to be a permanent component of the firearm.
Typically, a suppressor comprises an elongate tubular body that attaches in any suitable manner to a firearm barrel and provides for the movement of a projectile from the bore of a firearm barrel and through the tubular body of the suppressor. To facilitate sound suppression a number of internal baffles are typically positioned in stacked relation within a suppressor housing with baffle partitions disposed in axially spaced relation within the housing and with central openings in each baffle partition for projectile and propellant passage. A number of chambers that are defined between the internal baffles, causing the propellant gas to progress in serial fashion through the multiple chambers, with its velocity being diminished as it progresses. The partitions of the baffles are designed to reflect propellant gas and cause gas agitation within the chambers to slow the progress of gas transition through the suppressor and increase the dwell time and reduce the typically sharp and loud noise of the propellant gas being dischargeded from the suppressor. Propellant gas emitted from the bore of the barrel enters the much larger volume of the internal chamber of the tubular body and progresses serially from chamber to chamber, with the gas expanding and its pressure being diminished within each successive chamber.
When suppressors employ threaded connection between the various components the threads typically become fouled to the point that the threaded connections become difficult to separate. When the firearm is fired the suppressor housing is subjected to significant internal pressure which causes minute separation of the threaded connections and drive gunpowder residue into the threads, essentially causing locking of the threads which prevents them from being unthreaded, such as for cleaning. For this reason suppressors are typically manufactured by welding which prevents assembly and disassembly for cleaning of internal residue fouling and other service. When a welded suppressor device is employed, repeated firing of the firearm typically causes continuous fouling of the baffles, chambers and threads of the suppressor by accumulation of cartridge powder residue. Thus, when the threads of the suppressor or the threads of a firearm barrel become fouled it may be difficult or impossible to remove clean and reassemble the components of a suppressor device. This undesirable characteristic is common to most types of suppressors and represents a distinct disadvantage when servicing firearm components during field conditions. It often becomes necessary to return the suppressor to a repair or service facility to open the compressor and clean away cartridge powder deposits. It is desirable therefore, to provide a suppressor mechanism that effectively ensures isolation of the threaded connections that secure the suppressor components in assembly and at the same time provide for effective stability and durability of the suppressor mechanism and its connection with a rifle barrel.
Another disadvantage of firearm suppressor use is the problem of suppressor instability and the potential for coaxial misalignment that results from the threaded connection of the suppressor to the barrel of a firearm. The barrel of a firearm that is designed for attachment of a muzzle brake or suppressor is typically provided with a reduced diameter externally threaded section that is of fairly short length. An internally threaded section of a typical suppressor attachment end wall is also typically fairly short, thus causing the threaded connection to have minimal stability due to the typical length of the threaded connection of the suppressor with the firearm barrel. Thus, due to lateral impacts or other conditions a suppressor may become axially misaligned to the point that the edge of a moving bullet may contact an edge of a bullet port and interfere with the accuracy of an otherwise perfectly aimed shot. It is desirable to provide a suppressor mechanism that is exceptionally stable as well as protecting the internal threaded components from the undesirable characteristics of gunpowder residue buildup and fouling. U.S. Pat. No. 8,511,425 of Mark C. LaRue shows a suppressor device that employs a flash hider type device as a structural interface with a tubular suppressor housing. The flash hider structure shown in the '425 patent has spaced, angulated external support surfaces that are in engagement with corresponding spaced internal surfaces of a housing mount. This feature adds materially to the structural integrity of the coupling mechanism for securing a suppressor to the threaded end of a firearm barrel.
Typical commercially available firearm noise suppressors have multiple compartments within a single elongate, typically cylindrical tubular housing and define a single gas flow path. The baffles that are spaced within the suppressor housing create back-pressure within the suppressor that is relatively slow to be exhausted to the atmosphere. In many cases some residual gas pressure will remain within a suppressor at the time the auto-cycling mechanism of a gas energized firearm causes unlocking of the bolt member and begins to extract a spent cartridge case from the cartridge chamber of the firearm. When this condition exists a small amount of the residual propellant gas may be released from the bore of the firearm due to the back-pressure within the suppressor when unseating of a cartridge case begins, thereby directing a small amount of residual propellant gas toward the user of the firearm. This undesirable condition is known as “blow-back”. The presence of propellant gas can be objectionable from the standpoint of the comfort of the user. It is desirable, therefore, to provide a firearm noise and flash suppressor that provides for enhanced propellant gas exhaust to ensure optimum discharge of propellant gas and minimum gas exhaust dwell time so that little if any residual propellant gas pressure exists within the suppressor and firearm barrel when spent cartridge case extraction begins.
Though most sound suppressors achieve significant reduction of sound emission, the presence of gunpowder flash being emitted from the forward end of suppressors has continued to be a significant problem. During tactical rifle firing activities gunpowder flash is typically projected about a foot from the forward end of most suppressors because the rather high internal pressure causes burning gunpowder to pass rapidly through the suppressor and to be projected from the suppressor before it is completely consumed. This flash is very bright and is readily seen by opposing personnel, thereby causing the opposing personnel to direct rifle fire at the flash, resulting in significant danger to the firearm user. It is desirable, therefore, to provide a sound suppressor for firearms that minimizes internal propellant gas pressure and also serves as a flash suppressor by permitting sufficient dwell time to cause complete combustion of the propellant within the suppressor housing so that virtually no gunpowder flash occurs externally of the suppressor.
Briefly, the present invention involves a firearm noise and flash suppressor having an elongate tubular housing having front and rear end portions and defining an internal suppressor chamber. A plurality of baffles and spacers are positioned within the internal suppressor chamber and define aligned central projectile and propellant gas ports and define a plurality of propellant gas processing chambers that reflect and agitate the gas and slow the progress of propellant gas flow through the suppressor. The pressure of propellant gas is diminished by dividing gas emitted from the firearm barrel into a primary flow path within the baffles and a secondary flow path between the outer walls of the baffles and the internal wall of the elongate tubular housing. As the propellant gas progresses toward the front end of the elongate tubular housing the gas within the primary flow path is concentrated and directed to the projectile and gas exhaust port. Simultaneously the propellant gas of the secondary flow path is directed toward the circular array of angulated gas exhaust passages by flow passage sections in the form of external slots or grooves of a gas concentration member or by flow passage sections defined by spacing of the external surfaces of the gas concentration member and the internal surface of the suppressor body. The primary and secondary flow paths minimize the internal pressure of propellant gas being discharged vis the central projectile and propellant gas discharge port and the array of angulated propellant gas discharge ports and ensure enhancement of the timing sequence of the suppressor, thus minimizing the sharpness of suppressor noise and also minimize the potential for the presence of a visible flash in front of the suppressor.
As mentioned above, most firearm suppressors have components that are assembled by welding or brazing to eliminate the problem of gunpowder residue fouling. Threaded suppressor assembly is preferable, because a suppressor mechanism can be disassembled and cleaned or internal parts can be replaced. However, it is known, especially when extremely high pressure ammunition is used, that gunpowder residue will be forced into threaded connections by the effects of high pressure and by pressure energized distortion of the suppressor housing. This residue will typically interfere with and often prevent disassembly of the threaded connections by firearm users. Often, special equipment will be needed to accomplish unthreading and separation of threaded components, thus requiring that the suppressor be transported to a special servicing facility. By minimizing the internal propellant gas pressure by means of the dual flow path feature of the present invention, the problem of gunpowder fouling is largely eliminated. Suppressors can be disassembled and cleaned under field conditions, thus permitting firearm users to quickly restore fouled suppressors to effective service conditions.
The suppressor of the present invention has components that are designed for threaded assembly. Moreover, the threads of the various components are preferably left handed threads so that the natural shock and vibration of firearm use will not tend to loosen the threaded connections.